Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: RobertM on Jan 19, 2009, 20:17:41

Title: Rosette mosaic - labour of love !!!
Post by: RobertM on Jan 19, 2009, 20:17:41
I'm still not happy with this but here it is anyway.  With last nights data it's better than it was, plus I've got to move on after 6 imaging nights trying to get exposures for it through cloud and moon washouts.

Exposure details : Composed of 4 frames each of of which is made up of between 10 and 12 subframes of 20 mins, total exposure time approx 13 hrs.
Imagine equipment :  Starlight-Xpress SXV-H9 camera binned 1x1 through the Sky90@f/4.5 with an Astronomik 13nm Ha filter.
Guiding : ED80 and Atik16ic.

Half size jpeg image :

(http://farm4.static.flickr.com/3484/3209886699_02d469171e_b.jpg)


Link to full size jpeg image : http://farm4.static.flickr.com/3484/3209886699_2158ecd652_o.jpg (http://farm4.static.flickr.com/3484/3209886699_2158ecd652_o.jpg)
Title: Re: Rosette mosaic - labour of love !!!
Post by: Fay on Jan 19, 2009, 20:23:18
Well Robert, that certainly is nice. You have worked so hard on it. It knits together very well. It is the way to get it all in.

Why are you not yet happy?
Title: Re: Rosette mosaic - labour of love !!!
Post by: JohnP on Jan 19, 2009, 21:10:56
Robert,

What can I say except gobsmacked. Fantastic result & very deep. Love the wide FOV it really shows all the nebulosity off to the bottom left really well which you don't normally see. I had to rush upstairs & look at this on the full size monitor - The full size image is superb - very smooth & no hint of noise. The stars are tight & field very flat & I can't see any joins. I must say I really like it (just in case you couldn't tell).

Well worth the effort - I keep telling myself I must spend several hours on one object & after seeing this I think I will make the effort.

One question - can you explain why your stars always look so small & pinpoint...?

John
Title: Re: Rosette mosaic - labour of love !!!
Post by: Fay on Jan 19, 2009, 21:11:30
Robert, would you do a "labour of Love " again? Or was it a bit of an ordeal to do?
Title: Re: Rosette mosaic - labour of love !!!
Post by: Mike on Jan 19, 2009, 21:12:41
Absolutely superb Robert. Worth all that effort.
Title: Re: Rosette mosaic - labour of love !!!
Post by: Mac on Jan 19, 2009, 21:36:21
Fantastic detail.
Title: Re: Rosette mosaic - labour of love !!!
Post by: The Thing on Jan 19, 2009, 21:38:28
Incredible full size. Love it. Especially the dust lanes.
Title: Re: Rosette mosaic - labour of love !!!
Post by: RobertM on Jan 19, 2009, 22:05:11
Thanks for the kind comments guys and Fay.  It certainly did need a determined (I would say stubborn) effort to get it completed and felt like giving up more than once !  I couldn't have done this if I had been outside at the telescope all the time like Fay and the rest of you, some part of me would've fallen off with all the cold!

Fay, would do it again, not sure, maybe a two way mosaic a 4 way is definitely hard.  The difficulty is in getting all the subframes to marry up and be of the same quality and the time.  I can see a lot of imperfections but then I put it together so it's easy for me.

John,  If I was to say one thing about imaging nebula, it's that it does take time - longer subframes and lots of them.  All the real detail is very subtle and needs a lot of shots to get S/N up high enough to see it.  After you've tried it you won't look back!!  Small stars is down to accurate focusing + I think the Sky90 with flattener produces a wonderfully flat field which in turn means the stars are in focus all across the image.
Title: Re: Rosette mosaic - labour of love !!!
Post by: JohnP on Jan 19, 2009, 22:10:29
Thks Robert - Out of interest what Arcsec/pixel do you get with your current imaging setup..? John
Title: Re: Rosette mosaic - labour of love !!!
Post by: RobertM on Jan 19, 2009, 22:12:50
Focal length is 400mm and image scale is 3.34arcsec/pixel...
Title: Re: Rosette mosaic - labour of love !!!
Post by: Daniel on Jan 20, 2009, 00:50:42
That is absolutely spectacular, I was impressed just looking at the image you posted in here, then I clicked on the full size, WOW! love how round the stars are all the way across the field and I had to re-check that it was a mosaic, can't see the joins at all.

Awesome work, you've inspired me to do a mosaic some time, might have another crack at witches head!

Daniel
:O)
Title: Re: Rosette mosaic - labour of love !!!
Post by: MarkS on Jan 20, 2009, 07:24:31

Stunning!!

This is without doubt the best amateur image I've ever seen of the Rosette.  Your stars are round, you have captured amazing depth and the whole nebula is framed perfectly.  Because of the final image scale you have, the detail is extraordinary.

There is no way I would ever guessed it was a mosaic.  It was certainly worth the effort.

When are you adding the colour ;-)

Mark
Title: Re: Rosette mosaic - labour of love !!!
Post by: Fay on Jan 20, 2009, 08:32:07
Robert, you saying imaging from the garden would "make a part of you fall off".......................I trust your voice did not go up an octave after you had been to see me    :lol:
Title: Re: Rosette mosaic - labour of love !!!
Post by: RobertM on Jan 20, 2009, 09:06:49
Thanks again for the kind words.  The NW and SE were done near the last full moon so contrast is not as good as I would have liked.

I'll have to post one that comes out the same as on my screen at home, the jpegs always look washed out for some reason.  Does the Gallery allow TIFFs ?

Fay, the bits I was referring to were my fingers and toes ! both of which were at the limit after 2 hours at close to freezing.
Title: Re: Rosette mosaic - labour of love !!!
Post by: Mike on Jan 20, 2009, 09:41:59
Robert are you planning on adding any colour data to it?
Title: Re: Rosette mosaic - labour of love !!!
Post by: A.S.I.G.N_Baz on Jan 20, 2009, 10:23:33
Beautiful Robert. I can see the hard work, patience and effort in that!

Wow. Respect mate.

Baz.
Title: Re: Rosette mosaic - labour of love !!!
Post by: Fay on Jan 20, 2009, 10:29:16
Robert, I must say that your image is a great achievement, it is beautiful & you deserve it for all the extra effort you have put in
Title: Re: Rosette mosaic - labour of love !!!
Post by: RobertM on Jan 20, 2009, 10:50:03
QuoteRobert are you planning on adding any colour data to it?

It's tempting but it's another 6hrs worth of imaging ... the Canon might be worth a go.

Thanks Baz, I wish I had your skies !
Title: Re: Rosette mosaic - labour of love !!!
Post by: Rocket Pooch on Jan 20, 2009, 11:35:51
Good image Robert and it seems you are also a perfectionist as well, so you up for the additional 72 hours to do a HaO3SIIHb to complete the image :-)

Then maybe another week for the LRGB, then you will have done it well :-), only joking :-)
Title: Re: Rosette mosaic - labour of love !!!
Post by: RobertM on Jan 21, 2009, 08:29:06
Thanks SD, I do try, was fortunate this time though it doesn't always pay off.   I would only do the Rosette again with a larger format camera, shorter focal length or much larger aperture (any combination would be great!).

In the short term - No way Jose !
Title: Re: Rosette mosaic - labour of love !!!
Post by: RobertM on Jan 24, 2009, 10:56:27
I've now reconverted to jpeg thanks to both Jon and Mac's question and answer and the result looks much less washed out and more like the tiff...

(http://farm4.static.flickr.com/3444/3222461254_3dc9d7ca96_b.jpg)

and the full size version : http://farm4.static.flickr.com/3444/3222461254_f4c2f3f006_o.jpg (http://farm4.static.flickr.com/3444/3222461254_f4c2f3f006_o.jpg)
Title: Re: Rosette mosaic - labour of love !!!
Post by: Mac on Jan 24, 2009, 12:07:15
Just had a look at the full sized photo, and the detail is fantastic. :o
Title: Re: Rosette mosaic - labour of love !!!
Post by: Fay on Jan 24, 2009, 13:12:28
Perfection, Robert!